Production of high frequency electrical oscillations



April 15, 1941 H. BERTI-:LE voN GRENADENBERG 2,238,712

PRODUCTION OF HIGH FREQUENCY ELECTRICAL OSCILLATIONS Filed May 3l, 1940 Wwf.

ATTORNEY Patented Apr. 15, 1941 PRODUCTION OF HIGH FREQUENCY ELECTRICAL OSCILLATIONS' Hans Bertelc von Grenadenberg, Berlin-Schmargendorf, Germany, assigner to Patentverwerymugs-Gesellschaft mit beschrnkter Haftung Hermes, Berlin, Germany, a corporation of Germany Application May 31, 1940, Serial No. 338,082 In Germany January 31, 1939 Claims.` (Cl. Z50-27.5)

The invention relates to the production of high frequency electrical oscillations., and especially to such production with the help of a gas or vapor discharge device.

An object of the invention is to produce high frequency oscillations of well defined wave length, and of strong intensity with the aid of a gas or vapor filled discharge device.

Other objects and advantages of the invention will be apparent from the following description and drawing in which the figure is a cross sectional View through a preferred embodiment of the invention.

The invention relates to an arrangement and a process by which it is possible, with the help of a gas or vapor discharge path, to produce electrical oscillations of highfrequency and high intensity. It is possible to so arrange the discharge path that electrical oscillations of a xed wavelength are always produced.

The discharge path of a gas or vapor discharge device can be constricted at any place so that, at diierent parts of the discharge, there is only a small cross section for the emerging of the discharge. At this constriction, the electrical .carriers become bunchedand then emerge with the result that relatively high frequency electrical oscillations are produced. This constriction of the discharge path can be made in the form of a screen arranged between the cathode and anode. The location of the constriction can be very conveniently made in the anode arms which are connected to the rest of a vapor discharge device through constricted wall parts.

A preferred embodiment of the invention is illustrated in the figure in which the discharge device l is preferably of the type having a mercury pool cathode 2. The device also has one or more anode arms 3 in which are located the anode 4 as well as two other electrodes 5 and E.

The particular part 8 of the vessel, which contains the anode and these additional electrodes 5 and 6, has preferably a constriction I where this part extends towards the other portions of the vessel. The electrode 5 is preferably at the upper end or in the vicinity of the upper end of the anode arm, while the electrode 6 is preferably in the vicinity of the constriction itself. The anode 4 can be advantageously arranged in the center between both the electrodes 5 and S. As a discharge passes between the cathode 2 and the direct current anode 4, then the ionization equilibrium is disturbed at the place 'l because of the constriction of the discharge path. The result is that in the space behind the constriction, namely, the space 8, oscillations of the discharge carriers result, whose frequency depends on the ion or electron concentration in the plasma. The distance between the electrodes 5 and 6 can be advantageously chosen that it approximately equals half the wave length of the electric oscillations. The process could be compared in a certain sense, with air oscillations in a lip fife.

The maintenance of the desiredplasma condition in the oscillation production space, is helped by the continuation of a fixed temperature in this space, and by the choice of a xed current density. The temperature in the oscillation production space 8, is helped by a low temperature and, accordingly, it is preferable to provide a suitable cooling arrangement. This arrangement is preferably that of a cooling jacket which can also surround the constriction. The cooling jacket l0, illustrated in the drawing, has a cooling medium that should preferably provide a temperature between minus 10 C. and plus 10 C. A current density of the order of magni-` tude of about 5 amperes per square centimeter. has given good results,lbut the operation of the device is not limited to such a current density.

The boundary of the oscillation production space, is preferably covered with a high frequency resistance material 9. The high :Erequency oscillations are, of course, taken off from the electrodes 5 and 6 in the discharge space 8. The voltage applied to the main electrodes can amount to 5 to 10 kilovolts. It is possible, however, to use lower or higher supply voltages.

A discharge vessel, according to the invention, gives high frequency electrical oscillations of great intensity, whereby the stability of the oscillation process is already produced by the internal process of the motion of charged carriers in the oscillation production space 8, so that no outer connected parts are necessary by which the frequency is limited.

It is unnecessary in the arrangement, according to the invention, to utilize choke coils, condensers, resistances or a combination of these between the electrodes where the high frequency voltages occur. The formation of the individual electrodes can be done in different ways. Anode 4 can consist of metal or graphite. Electrodes 5 and 6 are advantageously made from suitably formed sheet metal. In the example shown, electrode 5 has the form of a flat plate which the anode lead Il is led through by means of insulation. The electrode E is formed as a cylindrical sheet ring so that the passage of charge carriers is not impeded in any way. This electrode can be made in the form of a mesh, which consists either-of mesh or gauze of Wires or of individual rods.

Electrode can also be structurally united with anode 4, so that one electrode gives the action of both electrodes. With the use of high voltages which occur between the individual electrodes,4

producing the discharge for the oscillation production space. Accordingly, I desire only such limitations to be imposed upon my invention as are within the spirit. and scope of the following claims.

What is claimed is:

. 1. An arrangement for the production of high frequency electrical oscillations which 'comprises an envelope having a gaseous atmosphere, an anode chamber and a cathode chamber, said envelope having a restricted opening leading from said anode chamber to said cathode chamber, an electrode within said anode chamber closely adjacent said restricted opening, another electrode .within said anode chamber spaced from said first mentioned electrod-e and an anode in said anode chamber intermediate said two electrodes.

2. An arrangement for the production of high frequency electrical oscillations which comprises an envelope having a gaseous atmosphere, an anode chamber and a cathode chamber, said envelope having a restricted opening leading from said anode chamber to said cathode chamber, an electrode within said anode chamber closely adjacent said restricted opening, another electrode within said anode chamber spaced from said rst mentioned electrode and an anode in said anode chamber intermediate said two electrodes and means maintaining the region of said anode chamber about said restricted opening at a temperature between 10 C. and +10 C.

3. A n arrangement for the production of high frequency oscillations comprising` an envelope having a cathode chamber containing a liquid cathode, an anode arm connected to said. cathode chamber through a restricted opening, a first electrode Within said anode arm closely adjacent said restricted opening, a second electrode Within said cathode chamber spaced from said first electrode, and an anode intermediate said rst and second electrodes.

4. An arrangement for the production of high frequency oscillations comprising an envelope having a cathode chamber containing -a liquid cathode an anode arm connected to said cathode chamber through a restricted opening, a rst electrode Within said anode arm closely adjacent said restricted opening, a second electrode within said cathode 'chamber spaced from said rst electrode, and an anode intermediate said rst and second electrodes, said rst and second e1ectrodes forming electrode terminals for high frequency oscillations.

5. An arrangement for the production of high frequency oscillations comprising an envelope having a cathode chamber containing a liquid cathode, an anode arm connected to said cathode chamber through a restricted opening, a first electrode within said anode arm closely adjacent said restricted opening, a second electrode within said cathode chamber spaced from said irst electrode, and an anode intermediate said first and second electrodes, and means maintaining the anode chamber adjacent said restricted opening at a temperature between 10 C. and +10 C'.

HANS BERTELE VON GRENADENBERG. 

